Hello,

I am very new to growing figs, although the fig bug hit me.  I have potted plants, all in black nursery pots.  I understand if the roots are hot growth is stunted, so what is common practice to keep the roots cool?

I had several ideas, but want to know what experience works for people.  I was thinking of painting the pots white, but I'm not sure how well paint would stick to the pots, or I was going to line up the pots and lean a 2 foot wide strip of plywood to shade the pots.

Any input would be greatly appreciated!

Phil

Hi - I'm pretty new too and also use black pots (throw aways from a neighbor's plantings). I try to keep them in the shade as much as possible. I also have them in a temporary greenhouse - the wind really dries them out and it's been pretty windy here. Also have had some heavy rain, so I don't want them getting broken either. So I threw a tarp over the top of the greenhouse for additional shade and leave it open. It doesn't get too hot in there - yet. After that, I may need to put them on the north-facing side of the house, mainly because that will provide the best windbreak. Or I'll have to build a windbreak on the south-facing side of the house. So far all the finagling is working, though :) Good luck.

Arne, Zone 6a

i just keep new cuttings in 1 gal under the shade. older trees, i water everyday around 4-5 pm. if i forget to water them the day before, i water well in the morning, then lightly around 4-5 pm. so far no rotted roots, and they are growing well.. but our temp is high 80 to mid 90 right now. if it goes into 100s, i water everyday.. sometimes twice. 

Phil,
Greenfig started a topic last year about measuring soil temperatures, http://figs4funforum.websitetoolbox.com/post?id=6480114 and from the dicussions painting or shading the pots will decrease the soil temperatures. Good Luck.

Thanks for your replies, especially the link. I should have known it was already covered.

Krylon makes a paint specifically for plastics. The big box home improvement places should have it.

I have a large [3' x 250'] roll of burlap at the house.
Would a wrap or two of this around pots keep the temperature down?

Good link that ascpete provided.  I've seen multiple other discussions on the forum too about techniques for this.  Some folks use boards next to the pots (to shade them from direct sun).  Some put light colored rocks on top (has this effect to some degree, but also other benefits).  Some folks bury their pots (or partially bury them) (that technique also has some other benefits).  I've leaned big flat rocks (creek rocks) against pots.  I've also used old sheets/rags (and I recall seeing someone on here made some fabric "pot covers").  And some do like Pete/bullet for small pots, though that doesn't really address the case of larger trees where you want them in full sun.  Probably I should post this instead in the discussion linked by Pete/ascpete.  Paul:  I do think that burlap would help, but not as much as lighter-colored cloth (like old bedsheet rags).  I suspect light paint (as james indicated) on the outside helps too, at least for black plastic pots.  For me (living in the cool northeast as I do), this isn't as much of an issue as for some of you guys who live in really hot sunny places.  <edit a few seconds later:  in the spring and fall, I actively make use of the warming radiant heat on a black pot... it kind of helps push the season at the cooler ends, with the soil in a black pot serving as a heat sink as well>.

Mike   central NY state, zone 5a

Tinfoil and a few pieces of tape works alright also.

Many growers who have containerized their figs, will sink the containers halfway into a garden bed and then mulch very heavily and completely cover the sides of the containers, up to the rim.  The mulch and soil surrounding the sunken containers will keep the roots cooler than if the containers were exposed to sunlight and ambient temperatures.  Allowing the roots to escape out of the drainage holes and then grow into the surrounding, cooler soil is also beneficial for the fig trees.  Just sever the meandering roots in August, by running a sharp spade down the sides of the containers, and then lift the containers out of the soil when trees go dormant.  Beware if your containers have drainage holes in the bottom.  You will not be able to sever the roots without straining to lift the containers.  All my containers have drainage holes ONLY on the sides of the containers for easy spade-trimming of roots.

Cool roots and sunny tops = figs.  ( I wonder if large, silvery Mylar bags will reflect heat and sun and keep the containers cooler, if wrapped around containers)

Frank

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EDIT:  Please see: Post follow-up postings #12 and #23 regarding .....trimming of roots.

DRPhil,

Can you get a delivery of wood chips from a tree service or the power company to put around them? That's what I am trying, pics in thread I just posted.

Frank,

You suggest severing the roots that have escaped buried pots in August. The only reason I can think of to do this is to once again encourage new roots to grow inside the pots. That doesn't seem worth the risk of overtaxing the now pot-only root system from a canopy that has become used to the extra work being performed by the now severed roots. Am I missing something?

I've dug up a few buried pots of trees/plants whose roots have escaped and have seen plenty of new root growth going on inside of the pots, so encouraging the plant to rely solely on the pot-only root system during the hottest month of the year seems counter-intuitive. My experience applying this technique to my figs is limited, but I've always severed them at or near dormancy with no obvious complications for the trees.

I get that insulation from the box store that is bubble rap with 2 sided foil. Cant think of what its called but for $50 you can insulate a bunch of pots and place them in full day sun. Still have to water daily in the heat of the summer but it keeps the root system about as cool as your gonna get it with out buring the pot. In the past Ive just used tinfoil and tape as suggested above on my blueberry plants and I did notice alittle slow down in growth during the dog days of summer from root temp. Im hoping this insulation Im using now will combat that problem and so far so good. I can stick my finger into the soil on the sunny side of the pot and its very cool to the touch apposed to pots that arent insulated. I believe this is going to be the ticket. Also a nice thing about keeping your pots in full sun and lifted off the ground with bricks or anything else keeps the roots in the pot as any roots that escape get air pruned cause its not sitting on the soil and the root system stays cool.

Mike, thanks for the detailed reply. I'm in 7a so I should keep the pot black for earlier starts and later finish, good point.

I have a lot of fig trees in black plastic nursery pots (300+) and the only thing I use to keep the temp down is watering at around 5PM which is the hottest part of the day here.
The plants I have in 15 gallon pots just sitting on the grass seem to produce quite well but they don't grow much.
The plants sitting on my concrete porch or my deck seem fine with a single watering and grow quickly. As they also produce well I'm beginning to believe my 15g pots are getting too warm.
I am curious about the temperature and it's effects and am shopping for a good thermometer (any suggestions appreciated) as I'm going to monitor and experiment on my larger older (5+ years) trees this summer. 

I was thinking a bale of hay sitting on the ground on the sunny side of the pot might work. Or perhaps an absorbent light colored cloth that would help drive down the temp by changing the black color and by evaporative cooling. Paint seems like a good idea if done before the pot is occupied as otherwise it seems like a lot of work. Perhaps white paint and a light cool blue design stenciled on to make the pots more attractive -- this is my problem -- one project turns into 3 or 4 way too easily. 
I'm always on the lookout for more attractive inexpensive large (15+ gallons) pots. I have yet to find any.

Mike,

Pete posted above the link to my thread ( thanks, Pete) where I tested the temps in containers. Like you, I was looking for a good thermometer to measure the temperature. After wasting some money and time, I got a few conventional thermometers and was quickly disappointed. The most interesting temperature was at the time when I was not home, second, the thermometer itself was warming up and distorting the data. So, a thin wire connected to an electronic board was the best solution I found. It collects the temp all the time and it can be easily plotted, you only need an old laptop or a PC to connect the board to.

As far as a protection, I think I would choose the paint as a last option. Any kind of shade works better, it can be burlap, wood/ carton panels, paper bag, rocks, bricks, other plants, etc. In addition, I would use mulch/ wooden chips on top.

hi Phil, IMO, if you berry the pots half way in the ground the roots will stay very cool and you don't have to water them as much :)

What do you guys think?

Edit: ooops, I should've just agreed with Rob, sorry just read the entire comments. I knew he was smart...

Posturedoc-

Thank you for calling my attention to a suggestion that I made back in post #10 regarding the spade-trimming of roots when growing containerized trees.  I should have been more careful when I posted the original recommendations, and should've written...."sever the meandering roots in late-August/early-September"......  Here in NYC (Zone-7), the night temps. in late August and in September, are starting to cool off, and trees are winding down the growing season. Leaves might even be turning yellow and dropping by this time of year. However, in other growing areas, especially in the warmer climates, trees may be still active for many more weeks before the onset of dormancy. 

As "Popsturedoc" suggested...trim roots just before dormancy, and do make adjustments according to your climate zones and growing conditions.

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My apologies for my lack of attention to details and for any confusion.


Frank

half burying the pots as recommended above works even when the temps are over 100.

green fig,
I spent hours last night looking at thermometers, moisture meters, pH meters and brix meters. I really want far more info then I'm getting and it doesn't seem like others are very interested. Or maybe they just have no clear alternatives or options.

Is there a reason no one tests their figs with brix meters. 

Oh well, hopefully by monitoring moisture and temp, etc. I may learn something about what I can improve. I'd love to know more about what you are doing. Maybe we cab share data.

Yeah, painting pots seems like no fun at all. I'm hoping to get some straw soon - or hay if I have to. I spent a bunch of time looking for alternatives to the pots I'm using. Self watering pots may be the answer but it'd be a huge investment in time and money and I hope to eventually put all my figs in ground (some inside). 

I guess the first thing to do is ret and determine if I actually have a problem. Your results make me lean toward the conclusion one exists. First I have over 200 plants to up pot. arrgghh